Online multiplayer games and other collaboration services have become increasingly popular as network communications have improved. Users who may be geographically distant from each other may communicate with an online service to participate together in games and/or other collaboration services. Typically, users run a client program that performs local processing and communicates with the online service to coordinate joint state of the multi-user game or service. For users to initiate participation in the same online game or online service, users may meet in an online lobby or other matching system that is associated with the online game or online service. However, if a person is not already communicating with the same lobby, or already participating in the same online service, the person may not be aware that a friend or colleague is participating. The friend or colleague can manually telephone the person or send a message with an identifier to invite the person to participate in the same online game or service. To reach people outside of the online game service, a message is typically sent through an independent messaging service, such as an online portal email service or instant message service, which is generally not limited to registered users of the online game service. However, this out-of-band messaging may be time consuming to find contact information and may distract from a current game session or other service session.
The other users that are contacted may not have the client program needed to participate in the online service. In that case, the other users typically access the online service independently to obtain the client program. Typically, the other users obtain a permanent copy of the client program, which may be costly, and may not be desired for permanent use. Sometimes, the other users can obtain a limited-capability client program that may not be able to join the same online session as the friend or colleague who informed the other users of the online service. Also, once the client program is installed, the other users may be required to search for the friend or colleague to join the same online session, or use the out-of-band communication to obtain address information from the friend or colleague to join the same online session.